The present disclosure relates to a percussion boring system and, more particularly, to an improved leading end assembly for a percussion boring system in the form of a horizontal directional drilling system.
A person having ordinary skill in the art understands that horizontal directional drilling systems are capable of directionally boring a winding channel in a substrate. These channels are commonly bored for any number of purposes such as for holding a product in the form of a conductive conduit, a fiber optic cable, a stretch of tubing, a sewer pipe, etc.
Percussion boring a subterranean channel for holding a product usually begins by boring a pilot channel in a substrate along a substantially predetermined path. The pilot channel has an entry point, where the leading end of the horizontal directional drilling system initially enters the substrate, and an exit point where the leading end of the system eventually emerges from the substrate. Notably, because operators of horizontal directional drilling (“HDD”) systems are often allowed very little deviation from the approved subterranean path and exit point location, an accurately set-up, calibrated and precisely steerable HDD system is desirable.
Current HDD systems used in the art, however, are limited in their ability to provide and maintain precise steering. The inability of HDD systems known in the art to provide precise steering functionality is due in some part to the reality that systems known in the art are defined by multi-component assemblies which have structural junction points that are inevitably compromised by the stress and strain of percussion boring. As one of ordinary skill in the art would understand, as the structural junction points in an HDD system become compromised due to wear and stress, the ability to accurately steer the system is also compromised. Further, because the configuration of HDD systems known in the art include a traditional bent sub component that introduces an abrupt elbow or bend in the leading end of the system, it is difficult for operators of the system to position a sonde component in a substantially level orientation such that accurate position feedback signals generated by instrumentation housed in the sonde may be received at the ground surface.
For at least the above reasons, and others, current HDD systems used in the art are difficult to accurately steer along an approved subterranean path such that an acceptable standard deviation for some applications is maintained. Therefore, there is a need in the art for an improved horizontal directional drilling system.